The present invention relates to solid fuel warm air furnaces, and more particularly to a warm air furnace in which inlet combustion air is preheated and selectively dispersed to several locations to promote complete combustion and high efficiency, and wherein a mixture of air and combustible gases in the firebox is ignited at the entrance to a controlled burn-out chamber.
Many currently known warm air furnaces using solid fuel (wood or coal) suffer from hard starting, incomplete combustion, and inefficient heat transfer to outlet air. Thus, inlet air admitted to the furnace is often too cold for complete combustion. This condition is even more acute at low levels of combustion and at start-up when attempting initially to ignite the fuel.
Also, in many furnaces of this type, combustion occurs at random and a significant amount of heat can be lost before the desired heat transfer occurs.